The present invention is directed to a support for a tie member tensioned between and anchored to different parts of a structure. The tensioned tie member is formed of steel wires, steel strands, rods or like enclosed within the protective casing, such as a diagonal cable in a stayed girder bridge. The support is provided at least at one of the points where the tie member enters into the structure to which it is anchored.
Tie members of this type used for anchoring component parts of a structure are, as a rule, positioned within a channel or passageway extending through the component part along with the protective casing so that the tie member can be moved longitudinally relative to the structure and anchored at a location opposite the point where the member enters into the structure. This is the situation where a diagonal cable for a stayed girder bridge is anchored to the tower and the roadway girder of a bridge.
Certain deformations occur in the transverse longitudinal directions of the diagonal cable, caused by alternating stresses due to temperature differences, and also due to live loads and wind loads which develop at the locations where the diagonal cable passes into the structure. If the diagonal cable is guided through the structure with sufficient play, different movements of the cable in the region of its anchor may produce bending moments which have an unfavorable influence on the strength of the cable. To reduce the effect of any movement or deformation, the cable can be reinforced in the region where it enters the structure, for example, it can be guided in a steel tube. In such an arrangement deformation is reduced and the fatigue behavior is improved. Further, transverse movements of the cable can be prevented if it is supported relative to the structure at the location where it enters the structure. In this way any transverse movements of the cable are spaced from the cable anchor, regardless of their origin.
Certain conditions must be provided for such a support, that is, there must be a certain amount of play between the cable and the structure during its installation. The structure should not be destroyed under a continuous load.